There are image forming apparatuses that estimate a remaining amount of toner accommodated in a toner cartridge. Various techniques for estimating a remaining amount of toner are examined. For example, there is a technique for estimating a remaining amount of toner on the basis of a rotation time of a toner supply motor, and the like. However, in this technique, an increase in a continuous rotation time of the toner supply motor may result in an increase in a deviation between an actual remaining amount of toner and an estimation result.